Lewis, Rebecca, Ph. D. (5. 4. 2009). „1939: The Three Posters (PhD Extract)”. Keep Calm and Carry On and other Second World War Posters: British Home Front Propaganda Posters of the Second World War. Архивирано из оригинала 02. 04. 2015. г. Приступљено 25. 12. 2013.
Lewis, Rebecca, Ph. D. (5. 4. 2009). „1939: The Three Posters (PhD Extract)”. Keep Calm and Carry On and other Second World War Posters: British Home Front Propaganda Posters of the Second World War. Архивирано из оригинала 02. 04. 2015. г. Приступљено 25. 12. 2013.